1. Field of the Invention
The present invention relates generally to medical devices and methods and more particularly relates to techniques for the treatment of obstructive sleep apnea.
2. Description of the Prior Art
The medical characteristics of sleep apnea have been known for some time. There are two generally recognized forms of the disease. The first is central sleep apnea which is associated with the failure of the body to automatically generate the neuro-muscular stimulation necessary to initiate and control a respiratory cycle at the proper time. Work associated with employing electrical stimulation to treat this condition is discussed in "Diaphragm Pacing: Present Status", by William L. Glenn, in Pace, Volume I, at pages 357-370 (July-September 1978). The second condition is known as obstructive sleep apnea. It is discussed at some length in "Obstructive Sleep Apnea: Diagnosis and Treatment", by Drs. Cook and Osguthorpe in Journal of South Carolina Medical Association, 81 (12): 647-651 (December 1985).
At present, a tracheostomy may be the treatment of choice for a number of patients when obstructive sleep apnea is severe, although systems employing continuous positive air pressure (CPAP) are now available. However, some interest has been displayed in electrical stimulation of the muscle tissue along the upper airway during respiration. U.S. Pat. No. 4,830,008 issued to Meer discusses a technique for electrical stimulation of the muscles of the upper airway in synchrony with the respiratory cycle. U.S. Pat. No. 4,506,666 issued to Durkan discusses such stimulation in conjunction with pressurized airflow supplied by a respirator.
The use of an implantable system for the treatment of obstructive sleep apnea by stimulation of the muscles of the upper airway is not indicated for all patients. Furthermore, for those patients for whom this therapy is indicated, placement of electrodes and sensors and adjustment of certain basic sensing and stimulation parameters is required. At present, the prior art does not teach an efficient method to accomplish the necessary screening of patients nor appropriate apparatus to assist in component placement and parameter adjustment.